Method and system for client-less viewing of scalable documents displayed using internet imaging protocol commands

ABSTRACT

A method and system for viewing a document containing at least one page and at least one image, the document being located on a server computer, including sending by a client computer a page display request to the server computer creating by the server computer a layout page containing a reference to stored image data, transmitting the layout page from the server computer to the client computer, sending an image data request to a remote computer according to the reference to stored image data, and transmitting requested image data from the remote computer to the client computer in response to the image data request.

FIELD OF THE INVENTION

The present invention relates to electronic documents containing rasterimages.

BACKGROUND OF THE INVENTION

PostScript is a resolution-independent format. Fonts can be enlarged orreduced in size to accommodate any viewing resolution. When a viewerzooms in or out of a document, the text characters automatically scaleaccordingly. Thus it can be said that font characters are “scalable.”

Similarly, graphical objects based on vector graphics consisting of linesegments and curves are also scalable. The line segments and curves canbe enlarged or reduced in size by appropriately modifying the pixelcoordinates of their control points.

Raster graphics, on the other hand, is not scalable. An image expressedin raster graphics is by its nature pixel resolution specific, and toenlarge or reduce the image involves digital image filtering andinterpolation. Moreover, a raster image cannot be stretched beyond itsoriginal pixel resolution without introducing artificial data.

SUMMARY OF THE INVENTION

The present invention provides an electronic document, including one ormore raster images, which is scalable. The raster images are referencedwithin the document through dynamically changing references, and it isthe control of the dynamic references that provides for the scalability.The scalable document of the present invention can be enlarged orreduced to any desired resolution, making the entire documentscalable—text characters, graphical objects and raster images.

Regardless of the viewing configuration, a raster image referencedwithin the scalable document of the present invention will automaticallyscale according to the viewing resolution. For example, suppose a6″×8″photograph is converted to a high quality digital image by scanningat 600 dots per inch (dpi). This produces a 3,600×4,800 pixel image,which is embedded into a page of the document.

When this page is viewed at normal size on a view monitor having 72 dpiresolution, the referenced image is scaled to 432×576 pixels forpurposes of display. If a user zooms in by a factor of two, to see aportion of the page containing the image at higher resolution, thereferenced image is scaled to 864×1,152 pixels. Thus the dimensions ofthe image referenced within the document automatically scale to twicetheir original values. If the document is printed on a 300 dpi colorprinter, the referenced image is scaled to 1,800×2,400 pixels in orderto produce as high quality a print as possible using the color printeras an output device.

In a preferred embodiment of the present invention the referenced imagesare located on one or more image servers on the Internet or any othersuitable computer network, and may be viewed on remote client computers.The raster images are not embedded within the scalable document, butrather are stored as separate files. The scalable document containsreferences to the raster images embedded therewithin, thus making thesize of the scalable document relatively small. Upon display, thedocument will include screen-size images within it. Upon delivery orprint, the document will include images scaled to the appropriate deviceresolution.

Each client computer preferably downloads only the portion of the imagedata that is necessary for satisfying a user display request, asdescribed hereinbelow. Continuing with the example above, the3,600×4,800 image uncompressed occupies a total of 51.84 MB (at 3 bytesper pixel). High fidelity compression typically reduces this by an orderof magnitude, to roughly 5 MB. Rather than requiring each client todownload the entire 5 MB of image data, the present invention onlyrequires the clients to download that portion of the image datanecessary to satisfy the user display request. The user display requestis significantly less than the entire image size, since the maximum sizeimage that can be viewed on a video monitor is the full video monitorpixel resolution, which may be 768×1,024 for example. Similarly whensaving or printing the document, the user may specify a resolution lessthan 600 dpi for the save operation, or the printer resolution may beless than 600 dpi, in which case the client only needs to download aportion of the full image data

The present invention also provides a rendition tool for convertingstandard documents with large high quality images into scalabledocuments, and a delivery tool for converting scalable documents intostandard documents. The rendition tool is used for creating Web-Readydocuments with screen-size images for interactive viewing. The deliverytool is used for saving documents containing high quality images at userspecified resolutions, and for printing such documents at resolutionsappropriate to specified output devices.

There is thus provided in accordance with a preferred embodiment of thepresent invention a method for viewing a document containing at leastone page and at least one image, the document being located on a servercomputer, including the steps of sending by a client computer a pagedisplay request to the server computer, creating by the server computera layout page containing a reference to stored image data, transmittingthe layout page from the server computer to the client computer, sendingan image data request to a remote computer according to the reference tostored image data, and transmitting requested image data from the remotecomputer to the client computer in response to the image data request.

There is also provided in accordance with a preferred embodiment of thepresent invention a system for viewing a document containing at leastone page and at least one image, the document being located on a servercomputer, including a client computer transmitter sending a page displayrequest to the server computer and sending an image data request to aremote computer according to a reference to stored image data, a layoutpage producer within the server computer creating a layout pagecontaining the reference to stored image data, a server computertransmitter transmitting the layout page to the client computer, and aremote computer transmitter transmitting requested image data to theclient computer in response to the image data request.

There is also provided in accordance with a preferred embodiment of thepresent invention a scalable document including at least one layoutpage, and at least one reference to stored image data, the at least onereference including at least one command for processing the stored imagedata.

There is also provided in accordance with a preferred embodiment of thepresent invention a method for converting a document containing at leastone image into a scalable document, including extracting at least oneimage from the document, storing the at least one image as stored imagedata, and replacing the at least one image by at least one reference tostored image data, the at least one reference containing at least onecommand for processing the stored image data.

There is also provided in accordance with a preferred embodiment of thepresent invention a system for converting a document containing at leastone image into a scalable document, including an object extractorextracting at least one image from the document, a storage device forstoring the at least one image as stored image data, and a referenceinserter replacing the at least one image by at least one reference tothe stored image data, the at least one reference containing at leastone command for processing the stored image data.

There is also provided in accordance with a preferred embodiment of thepresent invention a method for converting a scalable document into astandard document using at least one reference to stored image data, thescalable document containing at least one layout page, and the at leastone reference including at least one command for processing the storedimage data, including processing the stored image data in accordancewith the at least one command, producing at least one image, andpositioning the at least one image within the scalable documentaccording to positioning instructions within the layout page.

There is also provided in accordance with a preferred embodiment of thepresent invention a system for converting a scalable document into astandard document using at least one reference to stored image data, thescalable document containing at least one layout page, and the at leastone reference including at least one command for processing the storedimage data, including an image processor processing the stored imagedata in accordance with the at least one command, producing at least oneimage, and an image positioner positioning the at least one image withinthe scalable document according to positioning instructions within thelayout page.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and appreciated fromthe following detailed description, taken in conjunction with thedrawings in which:

FIG. 1 is a simplified illustration of a network configuration forInternet publishing in which a preferred embodiment of the presentinvention operates;

FIG. 2 is an illustration of an image portion and its relationship totiles in one of the resolution layers of a multi-resolution image, usedin connection with a preferred embodiment of the present invention;

FIG. 3 is a simplified illustration of an Internet publishing system forpublishing images over the Internet or any other suitable computernetwork, in accordance with a preferred embodiment of the presentinvention;

FIGS. 4A-4C are simplified illustrations of a page with text and imagesfrom a scalable document as seen at various display resolutions, inaccordance with a preferred embodiment of the present invention;

FIG. 5 is a simplified flowchart of the operation of a document viewerin accordance with a preferred embodiment of the present invention; and

FIG. 6 is a simplified illustration of a rendition tool for convertingstandard documents to scalable documents, and a delivery tool forconverting scalable documents to standard documents.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention concerns Internet publishing, and provides thecapability for storing electronic documents on a web server computer andenabling remote clients to interactively view, download and print thedocuments using web browsers.

Internet Publishing

A web browser is software running on a client computer that retrievesHTML pages from server computers using the HTTP protocol, and displaysthem. A hyper-text markup language (HTML) page is typically the basicdata structure for a web page that appears on a video monitor wheneverone is using the Internet. An HTML page typically contains layoutinstructions along with text, graphical objects, links and more. Objectsreferenced in an HTML page but located at remotes sites are typicallyreferenced by a universal resource locator (URL), which contains a fullIP address indicating where the object is located in addition tooptional instructions for processing the object. Two well-known webbrowsers are Netscape Communications Corporation's Netscape®Communicator and Microsoft Corporation's Internet Explorers®.

A web server is software running on a server computer that deliversrequested HTML pages to web browsers using the HTTP protocol.

Documents archived on a server computer can be accessed by remote clientcomputers by means of web browsers. If a document is not in HTML format,additional server-side or client-side processing may be necessary. Suchserver-side processing involves auxiliary software on the server forconverting each document page requested into HTML format for viewing bythe client. Client-side processing involves auxiliary software used withthe browser, in the form of a plug-in, an Active-X control or a Javaapplet, for interpreting the non-HTML format.

There is a general disinclination on the part of users to downloadclient software, as this interrupts the web browsing and invasivelyinstalls new software on the user's computer. For example, if a useraccesses a URL that requires a plug-in while browsing the web, he mustdownload the plug-in software, exit the browser, install the plug-in andthen re-initiate the browser. When server-side processing is used insuch a way that no auxiliary client software is needed other than theweb browser, the application is referred to as being “client-less.”Client-less applications tend to be more favorable, as they do notrequire the user to interrupt his web browsing or to place additionalsoftware in his computer.

The present invention, as described hereinbelow, enables client-lessapplications to interactively view remotely located electronic documentsby scaling and moving within pages.

Reference is now made to FIG. 1 which is a simplified illustration of anetwork configuration for Internet publishing in which a preferredembodiment of the present invention operates. A server computer 110stores documents and HTML pages for remote access by multiple clientcomputers 120. Server computer 110 contains a web server 130 for servingfiles 150 and HTML pages 160 to client computers 120 in response torequests 170. Client computers 120 typically contain web browsers 140for displaying HTML pages 160, and typically use the links in HTML pages160 to request documents and other HTML pages from server computer 110.

In a preferred embodiment of the present invention, the HTML pages 160contain links 180 to objects 190, such as raster images, stored onremote computers 200 connected to the Internet.

Web browsers 140 typically can display only a limited number ofdifferent page formats, such as HTML. In order for a web browser todisplay a document that is not in one of the supported formats,auxiliary client software 210 may be needed to supplement the webbrowser so that it can interpret the document format. Alternatively,server software 220 can be used to convert the document into HTMLformat, so that it is ready for display by the web browser when thedocument arrives at the client computer. In this latter case there is noneed for client software 210, and the application is client-less.

Resolution Independence

The present invention uses resolution independent image data requests toachieve scalability of raster images referenced within documents.Resolution independence is a technique for processing large digitalimages based on the tenet that an image can be considered as a continuumof color values distributed over a rectangular spatial region. That is,an image can be considered as a two-dimensional continuous spatialsignal, analogous to a onedimensional continuous time signal. Carryingthis analogy further, a continuous “resolution-independent” image can beconverted to a discrete spatial array by sampling at appropriatefrequencies in each dimension, just as a continuous time signal can beconverted to a discrete time signal by sampling at an appropriate rate.

Resolution independent images are modeled by a continuoustwo-dimensional coordinate system with coordinates x and y ranging overa rectangular region that can be normalized as the unit square, 0≦x≦1,0≦y≦1. Specifically, a resolution independent image is determined by avector-valued function ƒ(x, y), with ƒ(x, y) indicating the color valueat location (x, y) as x and y range over the unit square. Color istypically prescribed by multiple values within a standard color space,such as RGB or CMYK.

In distributed imaging systems, one of the most common user requests isfor access to a rectangular portion of an image. A rectangular portioncan be described by a set of four values (t, l, h, w), where (t, l) arethe coordinates of the top-left corner of the portion, h is the heightof the portion and w is the width of the portion—all four numbers beingrelative to the normalized unit square. Thus, for example, the portion(0.25, 0.35, 0.15, 0.3) denotes the rectangle extending from top-leftcorner (0.25, 0.35) to bottom right comer (0.4, 0.65). The height ofthis rectangle is 15% of the total height of the image, and its width is30% of the total width of the image.

Any digital image, no matter how large, does not contain moreinformation than the sum total of its color values. Thus, considering adigital image to be a continuum of color values is an idealization. Theextent to which this idealization applies is up to the point where thepixel dimension of the original image is exceeded. For large digitalimages, this leaves enough room to make the idealization a practicalone. This idealization is analogous to the applicability of continuummechanics to physical bodies up to the point where the atomic level isreached.

Discretization

The present invention involves three types of client requests fordocuments: (i) interactively displaying and navigating through thedocument on a video monitor, (ii) printing the document on a local ornetwork printer, and (ii) delivering the document to the clientcomputer; i.e. downloading the document, such as by means of a “Save As”operation. In order to display, print or save a resolution-independentimage included within a document, the image must first be converted to apixel array, which is a raster array of discrete pixel values. Therequired dimensions of the pixel array determine the samplingfrequencies, and as long as these frequencies are each greater than orequal to one, the conversion can be accomplished without introducingartificial data. Every request for displaying, printing or saving aportion or all of an image can be described by a rectangle inresolution-independent coordinates, as described hereinabove, togetherwith a pair of discrete pixel dimensions representing the width andheight of the pixel array. The pixel array can represent a view windowfor display, a dot array for printing or a raster array for saving araster image.

Consider, for example, a 6″×8″photograph that is converted to a highquality digital color image by scanning at 600 dots per inch (dpi). Thisproduces a 3,600×4,800 pixel digital image. In order to view this entireimage on a video monitor having 72 dpi resolution, the image has to bescaled to 432×576 pixels, which amounts to a reduction in size of theoriginal image by a factor of 25/3=8.33 in each dimension; that is, thesampling frequency is 8.33 in each dimension. Using the resolutionindependent paradigm, the digital image is idealized as a resolutionindependent image, the rectangular portion designating the entire imageis (0, 0, 1, 1) and the required view window size is 432×576 pixels.

If this same digital image is to be printed on a 300 dpi resolutioncolor printer, then the relevant rectangular portion is (0, 0, 1, 1) andthe required dot array size is 1,800×2,400 pixels. This corresponds to asampling frequency of 2 in each dimension.

If a user wishes to display the top left quadrant of the image in a450×600 view window, then the relevant resolution independent portion ofthe image is (0, 0, 0.5, 0.5) and the required view window size is450×600 pixels. This corresponds to a sampling frequency of 4 in eachdimension. On the other hand, if the user had wanted to save the topleft quadrant of the image as a 2,400×3,200 pixel array, this wouldcorrespond to a sampling frequency of ⅔in each dimension. In this lattercase, the limits of the resolution independent idealization areexceeded.

Image distribution systems that accommodate interactive display,printing and saving (i.e. downloading) can operate by (i) storing largedigital images on server computers, (ii) accepting user requests forimage data from remote client computers, each request being determinedby a resolution independent rectangular portion and a pixel array size,and (iii) responding to such requests by transmitting appropriate imagedata from a server to a remote client. The Flashpix image format and theInternet Imaging Protocol, as described hereinbelow, were designed tomake Internet image distribution systems as efficient as possible, byadministering a “just enough data” policy and transmitting only theminimal amount of image data necessary to satisfy a client request.

Referring back to the abovementioned example, the 3,600×4,800 originalimage occupies a total of 3×3,600×4,800=51.84 MB uncompressed, at apixel depth of 3 bytes per pixel. High fidelity compression such as JPEGtypically reduces this by an order of magnitude to roughly 5 MB. In thefirst scenario above, where the user requests the entire image to bedisplayed at 432×576 pixel resolution, the image to be displayedoccupies only 3×432×576=746,496 bytes uncompressed, which corresponds toapproximately 75 KB compressed. Rather than transmit the entire 5 MB ofimage data from the server to the client, an efficient imagedistribution system transmits only the 75 MB of data, or slightly moreas described below in reference to caching, necessary to render thedesired display image.

Flashpix Image Format

Multi-resolution tiled (MRT) image formats are particularly well-suitedfor storing resolution independent images in such a way that specifiedrectangular portions of such an image can be efficiently generated atspecified pixel resolutions. An MRT format stores the original imagetogether with the successively reduced versions of the image. Moreoverthe image data for the original image and for each reduced versionthereof is partitioned into blocks called tiles. As such, an MRT formatis redundant in that the reduced versions of the image can be generatedform the original image data but are nevertheless stored in the file.However, the advantage of the MRT format is that lower resolution imagedata is readily available, and the tile structure makes it simple toaccess rectangular portions of the image.

FLASHPIX, a trademark of the Digital Imaging Group (DIG), is an exampleof an MRT image format. A Flashpix image is generated by starting withan original image and recursively subsampling it at half of the previousresolution. The recursion continues until the final sub-sampled image isreduced to a size of 64 pixels or less in each dimension. Eachresolution level is partitioned into image tiles that are 64×64 pixelsin size, and the individual tiles can be stored as uncompressed or JPEGcompressed image data. A reference for Flashpix is the document“Flashpix Format Specification,”© 1996, 1997, Eastman Kodak Company, thecontents of which are hereby incorporated by reference.

Referring back to the abovementioned example, the 3,600×4,800 pixelimage would be stored as a Flashpix image with eight resolution layersas follows:

Layer #7: 3,600×4,800

Layer #6: 1,800×2,400

Layer #5: 900×1,200

Layer #4: 450×600

Layer #3: 225×300

Layer #2: 113×150

Layer #1: 57×75

Layer #0: 29×38

Each of these layers would be partitioned into a set of tiles, each tilebeing 64×64 pixels in size.

Reference is now made to FIG. 2, which is an illustration of a portionof an image and its relationship to tiles in one of the resolutionlayers, used in connection with a preferred embodiment of the presentinvention. FIG. 2 illustrates how tiles are identified to satisfy a userrequest to view the top left quadrant of the above Flashpix image in aviewing window of 240×320 pixels. The requested image portion is (0, 0,0.5, 0.5), using the notation for resolution independent rectanglesdescribed hereinabove, and the requested pixel dimensions are 240×320.This corresponds to a sampling frequency of 7.5 in each dimension.

The closest resolution layer in the Flashpix image that does not exceedthis sampling frequency is Layer #5, designated by reference numeral230, which has a sampling frequency of 4 in each dimension. Therequested image portion can be generated by reducing the top leftquadrant of the 900×1,200 resolution layer by a factor of 8/15. Asillustrated, Layer #5 has 15 rows of tiles, each row having 19 tiles,the tiles being designated by reference numerals 240. Observe that someof the tiles extend beyond the right and bottom borders of the image inLayer #5. To obtain the top left quadrant image portion (0, 0, 0.5, 0.5)designated by reference numeral 250, it is necessary to extract datafrom the first 10 tiles in each of the top 8 rows of tiles, as these arethe tiles that overlap with the image portion (0, 0, 0.5, 0.5). If thetiles are numbered serially from 0 to 284, as illustrated in FIG. 1,then the necessary tiles are 0-9, 19-28, 38-47, 57-66, 76-85, 95-104,114-123 and 133-142.

These tiles can be retrieved from the Flashpix image and combined into asingle image of dimensions 512×640 pixels. The combined image can thenbe cropped to a size of 450×600 pixels by cutting off the excess tilespillage at the right and bottom borders. The cropped image can bereduced by a factor of 8/15 to the desired target size of 240×320pixels. This is more efficient than beginning with the full 3,600×4,800pixel original image and re-sizing by a factor of 2/15. The final240×320 image may be JPEG compressed and transmitted to the client forembedding in an HTML page.

In the above example, Layer #5 was chosen rather than Layer #4, sincethe top left quadrant of Layer #4 would have produced an image of225×300 pixels, which would then have had to be enlarged by a factor of16/15. Typically it is desirable to avoid enlargements, since theyintroduce artificial data.

Flashpix image data can be specified in standard RGB or PhotoYCC colorspaces, or in another calibrated color space designated by anappropriate International Color Consortium (ICC) profile. The image datacan also include an opacity channel to specify transparent and opaqueparts of the image.

In addition to image data, Flashpix files contain meta-data, which isauxiliary data to the image. Meta-data includes information about theimage, such as creator, contents, copyright, date and time created, dateand time last modified, camera information, scanner information, etc.The meta-data also includes parameters for transformations to be appliedto the image, such as rotations and scaling, general affine spatialtransformations, contrast adjustment, color space transformations, etc.

Internet Imaging Protocol

A recently developed protocol, the Internet Imaging Protocol (IIP),specifies a method for a user to request portions of an image at aspecific resolution. A reference for IIP is the document “InternetImaging Protocol,” © 1997 Eastman Kodak Company, Hewlett-Packard Companyand Live Picture, Inc., the contents of which are hereby incorporated byreference.

A server with server-side software that supports IIP is referred to asan “image server.” There are two generic ways to request image data froman image server using IIP; server-side processing of the request, andclient-side processing of the request.

To illustrate server-side processing, suppose a user with a viewingwindow of 480×640 pixels desires to view the full image from theabovementioned example whose original size is 3,600×4,800 pixels. Inaccordance with IIP, the full image at a 480×640 pixel resolution for aninitial view can be requested using the following IIP request,containing a set of IIP commands:

OBJ=iip,1.0&FIF=<image-name>&WID=640&HEI=480&CVT=jpeg.

This request specifies the version of IIP being used by means of theOBJ=iip,1.0 command. It specifies the desired image by means of the FIFcommand, and specifies the width and height of the viewing window bymeans of the WID and HEI commands, respectively. The last command, CVT,specifies the format of the image to be sent. As indicated above, theCVT command instructs the image server to convert the image data to theJPEG image format. Typically, the JPEG image transmitted from the imageserver to the client is embedded within an HTML page.

For the image server to process the above IIP request, the server mustanalyze the original image and generate a JPEG image with the requestedspecifications, specifically the desired portion and dimensions.

Similarly, the IIP request

OBJ=iip,1.0,&FIF=<image-name>&RGN=0.25,0.35,0.4,0.6&WID=640&HEI=320&CVT=jpeg

specifies the rectangular portion with upper left coordinate at(0.25,0.35), height of 0.4 and width of 0.6, in resolution independentcoordinates, and a viewing window of 320 pixels height by 640 pixelswidth. It also specifies that the designated image portion is to bereturned as a single JPEG image. It can be verified that the requestedimage portion corresponds to a sampling frequency of 6 in eachdimension.

In the above examples the image server does the image processingnecessary to create a “ready for display” image for the client webbrowser. Alternatively, in a client-side processing application, theserver can simply send the requested tiles to the client, and leave itup to client software to stitch the tiles together and resize.

To illustrate client-side processing, the IIP request

OBJ=iip,1.0&FIF=<image-name>&TIL=4,0-5

requests the image server to send tiles 0-5 from resolution Layer #4within the designated image. Referring back to the Flashpix image fromthe abovementioned example, Layer #4 is the 450×600 version of theimage. This version has 8 rows of 10 tiles. Tiles 0-5 within this layerare the first six tiles of the first row.

Tile ranges are interpreted as rectangular ranges of tiles, rather thanserial ranges, with the first tile in the range representing the upperleft tile in the rectangle, and the second tile in the rangerepresenting the lower right tile in the rectangle. Thus, referring backto FIG. 2, the 80 tiles that overlap with the desired image portion(namely, the top left quadrant) can be accessed by the single IIPrequest:

OBJ=iip,1.0&FIF=<image-name>&TIL=5,0-142.

IIP is independent of any particular image format. A CVT request for adesired image portion at desired pixel dimensions and a TIL request fortiles can be applied to any image format. For example, a JPEG imagecould be the object of a CVT or TIL command. If the image is not alreadyin multi-resolution format, then the server is required to create theappropriate resolution from the original image data on-the-fly in orderto process the IIP request. It may be appreciated that the redundancy instorage for a multi-resolution image format such as Flashpix balancesthe processing necessary to produce these resolutions on-the-fly for asingle-resolution image format such as JEG.

Scalable Documents

The present invention concerns scalable documents—i.e., documentsincluding raster images that are scalable. The raster images arereferenced within pages of the document by dynamic references, and it isthe control of the dynamic references that provides for the scalability.The pages of the scalable documents of the present invention can beenlarged or reduced to a wide range of resolutions, making the entiredocuments scalable—text characters, graphical objects and raster images.Regardless of the view, print or save parameters, a raster image in ascalable document automatically scales according to the desiredresolution.

The raster images referenced within the pages of a scalable document canbe located on image servers connected to the Internet or any othersuitable computer network, viewed interactively, saved on remotecomputers and printed on network printers. Moreover each client computeraccessing the scalable document preferably downloads only the portion ofthe image data that is necessary for satisfying the user display, printor save request.

The scalable document may also have raster images embedded therewithinin their entirety, and not merely by references. However, the presentinvention concerns raster images that are referenced but not storedwithin the document.

Storage of references to raster images rather than the images themselveswithin a document achieves two advantages. The first advantage is thatit significantly reduces the size of the document, since raster imagestend to be large data structures. This makes it possible for a user toquickly download all or parts of the document without the images. Theuser can interact with the document, such as by advancing pages orclicking on links, before the image data is downloaded.

The second advantage of storing references rather than raster images isthat it provides for scalability; i.e. it provides an efficient way toautomatically scale the raster image according to a desired display orprint resolution. Consider the abovementioned example of a documentcontaining an image that was scanned at 3,600×4,800 pixel dimensions.The original image is stored on an image server as an approximately 5 MBfile, and not within the document. The document references the originalimage by means of a link.

If a user interactively displays the document on a video monitor, hecannot typically display the image contained therewithin at the full3,600×4,800 pixel dimensions, as video monitors do not support pixelarrays this large. The display resolution depends on the resolution ofthe video monitor, the portion of the image being viewed and the portionof the video monitor on which the image is being viewed. For example,suppose the user is currently viewing the top left quadrant of the imagein a viewing window of 240×320 pixel dimensions. If the original imagewas scanned at 600 dpi, as above, then the current view corresponds to adisplay resolution of 160 dpi., only 26.7% of the original resolution.

Moreover a viewing window of 240×320 only requires 230.4 KB ofuncompressed image data (at a color depth of three bytes per pixel),which is approximately 23 KB of compressed image data, using the 10:1ratio for high quality compression recited above. Using the presentinvention, only the 23 KB of image data necessary to render the desireddisplay is downloaded. Moreover, as described hereinbelow, once thisdata is downloaded it is cached for subsequent use, so that whenever thesame data is required again, it is not necessary to download it from theimage server.

As can be seen from the abovementioned example, a user's requesttypically comprises (i) a designated portion of an image to be viewed,such as the top left quadrant, and (ii) a designated pixel dimension fordisplay, save or print, or equivalently a designated resolution (in dpior similar units) for display, save or print. According to a preferredembodiment of the present invention, the request can be encoded as alink within the document containing a request with commands, such as IIPcommands, for retrieving a specific typically rectangular portion of animage at specific pixel dimensions.

The link to a raster image within a scalable document contains anidentifier indicating the location of the raster image and a commandspecifying the rectangular portion needed and the required display pixeldimensions. The scalability of the document is achieved by dynamicallychanging the appropriate rectangular portion and appropriate displaypixel dimensions that form part of the link, as a user interactivelypans and zooms in and out of the document, and as the document isprinted at various printer resolutions.

Reference is now made to FIG. 3 which is a simplified illustration of anInternet publishing system of the present invention for publishingimages over the Internet or any other suitable computer network inaccordance with a preferred embodiment of the present invention. Anelectronic document management system 310 contains several scalabledocuments 320. Each scalable document typically contains page layoutinformation, font references, text characters and references to rasterimages 330 in the form of links. Scalable document #1 contains links toimage #2 and image #3. Scalable document #2 contains links to image #1and image #4. The raster images 330 are stored on an image server 340. Adocument viewer 350 accesses scalable document #1 via an Internetconnection. Document viewer 350 may be part of a web browser or,alternatively, it may be auxiliary client software.

When document viewer 350 initially accesses document #1, an initialdefault display request for an initial page of the document containingimage #2 and image #3 therewithin is transmitted from the client to thedocument manager. In turn, the document management system 310 preferablycreates an HTML page with an appropriate layout for viewing the initialpage and transmits the HTML page to document viewer 350. The layoutincludes positioning information for image #2 and image #3, and for textand other objects in the page. However, the HTML page does not containthe data for image #2 and image #3, but instead contains references,such as URLs, having image processing and data transfer commands, suchas IIP commands, for retrieving the necessary image data from imageserver 340. Document viewer 350 transmits the IIP commands to imageserver 340 to retrieve the image data from image #2 and image #3necessary for rendering the default display of the initial page. Imageserver 340 processes the images to obtain the requested image data, andtransmits the image data to client document viewer 350. Document viewer350 then embeds the image data into the initial page of document #1 anddisplays the HTML page with image #2 and image #3 embedded therewithin.

A user interactively views document #1 by advancing back and forththrough pages, by zooming in and out of a page, and by navigating aroundthe page. Each interactive user request for viewing document #1initiates a corresponding display request for a specific requested pageor portion thereof that is transmitted from document viewer 350 todocument management system 310. As described above, the display requestis translated into an HTML page containing an URL with an IIP requestspecifying appropriate rectangular portions and viewing pixel dimensionsfor an image within the page. The HTML page is transmitted from documentmanager 310 to document viewer 350, and the IIP request therewithin issent from document viewer 350 to image server 340. Image server 340processes the images to execute the IIP command and transmits thegenerated image data to document viewer 350. Document viewer 350 thendisplays the HTML page and the image data.

In an alternate embodiment of the present invention the IIP request maybe sent by document manager 310 to image server 350. Image server 350may transmit the generated image data to document manager 310 ordirectly to document viewer 350.

Reference is now made to FIGS. 4A-4C which are simplified illustrationsof a page containing text and images from a scalable document as seen atvarious display resolutions, in accordance with a preferred embodimentof the present invention. A scalable document 410 is accessed by aclient and displayed using an initial default view, as shown in FIG. 4A.The page contains font text data 420 and a raster image 430.

A user interactively views scalable document 410 and may zoom in on aportion of the page. The scalable document is automatically re-scaled sothat both the text 440 and the image 450 are enlarged, as shown in FIG.4B. The user may further zoom in on a portion of the page, and thescalable document is automatically re-scaled again so that both the text460 and the image 470 are further enlarged, as shown in FIG. 4C. In analternative embodiment of the present invention, the image can be openedin a separate window in the viewer, and interactively viewed within theseparate window.

Universal Viewing

As described hereinbelow, the present invention combines methods fromUniversal Viewing with the scalability of fonts and vector graphicalobjects to produce an integrated fully-scalable document for interactiveviewing. Specifically, the present invention uses methods from UniversalViewing to dynamically adjust the IIP requests within links ofdocuments. Co-pending patent applications, U.S. Ser. No. 08/979,220filed on Nov. 26, 1997 and U.S. Ser. No. 09/095,459 filed on Jun. 10,1998, both entitled “A Method and System for HTML-Driven InteractiveImage Client,” the contents of which are hereby incorporated byreference, describe a new technology for interactive navigation of largeimages over the Internet or any other suitable computer network, withoutthe use of auxiliary client software. This technology is referred toherein as “Universal Viewing.”

Universal Viewing operates through the use of HTML pages, and enables auser to pan and zoom in and out of large images. It does not require useof a plug-in, a Java applet, an Active-X control, nor any other softwarethat must be downloaded to a client computer. Universal Viewing operatesby using server-side rendering as described hereinabove, along withappropriate dynamically changing IIP requests contained in referenceswithin an HTML page, corresponding to interactive user navigationrequests.

Referring to the abovementioned example, an initial full view of theimage can be generated within an HTML page by including the request withIIP commands:

OBJ=iip,1.0&FIF=<image-name>&WID=640&HEI=480&CVT=jpeg.

These IIP commands serve to produce a view of the full image in a640×480 view window on a user's video monitor.

Suppose the user clicks near the top left corner of the image in orderto zoom in on the top left quadrant of the image. The client web browsersends to the server the location of the coordinates where the userclicked, and in turn the server replaces the IIP commands within theHTML page with the following revised commands:

OBJ=IIP,1.0&FIF=<image-name>&RGN=0.0,0.0,0.5,0.5&WID=640&HEI=480&CVT=jpeg.

As a result, the top left quadrant of the image, corresponding to theindicated region, appears enlarged to fill the 640×480 view window onthe user's video monitor.

Suppose next that the user clicks on a directional arrow in the display,pointing to the right, in order to pan to the right. The web browsersends to the server a URL activated by the user click on the rightwardpointing directional arrow, and in turn the server replaces the IIPcommands within the HTML page with the following commands:

OBJ=iip,1.0&FIF=<image-name>&RGN=0.0,0.25,0.5,0.5&WID=640&HEI=480&CVT=jpeg.

These commands produce a view of the portion of the top half of theimage centered between 25% and 75% of the full image width, within a640×480 view window.

Finally, suppose that the user next clicks on a zoom button to zoom inat the center of the image portion currently being displayed. The clientweb browser sends to the server a URL activated by the user click on thezoom button, and in turn the server replaces the IIP commands within theHTML page with the following commands:

OBJ=iip,1.0&FIF=<image-name>&RGN=0.125,0.375,0.25,0.25&WID=640&HEI=480&CVT=jpeg.

These commands produce a view of the portion of the image between 12½%and 37½% of the image height, and between 37½% and 62½% of the imagewidth—i.e., the central portion of the previous region, enlarged to fillthe 640×480 view window.

Reference is now made to FIG. 5, which is a simplified flowchart of adocument viewer in accordance with a preferred embodiment of the presentinvention. Illustrated in FIG. 5 is a sample interactive viewing sessionduring which a client interactively views a document containing a highquality image stored on a server computer. In the sample session theclient views an initial page of the document with an image. The clientclicks to zoom in on the page, then navigates to move to the right andthen advances to a next page.

At step 510 the client clicks on a URL to a document file in a web page.At step 520 the server creates a first HTML page appropriate to view aninitial page of the document with a URL containing an IIP request forthe image contained therein, and transmits this page to the client. Atstep 530 the client receives the HTML page with the URL, and a webbrowser within the client, upon processing the page, accesses the URLthat references the image and sends the IIP request within the URL to animage server containing the image. At step 540 the image serverprocesses image data to execute the IIP request and generate therequested image, and then transmits the requested image to the client.At step 550 the web browser displays the HTML page with the image.

At step 560 the user, while viewing the first HTML page, clicks to zoomin on a portion of the displayed page. The zoom can be activated by theuser clicking on an icon such as a magnifying glass, or by clicking at alocation within the image, or both. At step 570 the server creates asecond HTML page with a URL containing an IIP request corresponding tothe zoomed portion of the initial image that is to appear in the zoomedportion of the initial page, and transmits this page to the client. Atstep 580 the client receives the second HTML page with the URL, and theweb browser, upon processing the second page, accesses the URL thatreferences the zoomed image portion and sends its IIP request to theimage server. At step 590 the image server processes image data toexecute the IIP request and generate the requested image, and thentransmits the requested image to the client. At step 600 the web browserdisplays the second HTML page with the zoomed image portion.

At step 610 the user, while viewing the second HTML page, clicks to moverightward within the displayed page. Since the second HTML page onlydisplays a portion of the initial document page, the user must navigateto see other portions of this page. At step 620 the server creates athird HTML page with a URL containing an IIP request corresponding tothe portion of the initial image that is to appear in the rightwardzoomed portion of the initial page, and transmits this page to theclient. At step 630 the client receives the third HTML page with theURL, and the web browser, upon processing the third page, accesses theURL that references the rightward zoomed image portion and sends its IIPrequest to the image server. At step 640 the image server processesimage data to execute the IIP request and generate the requested image,and then transmits the requested image to the client. At step 650 theweb browser displays the third HTML page with the rightward zoomed imageportion.

At step 660 the user, while viewing the third HTML page, clicks toadvance to the next page within the document. In the embodimentillustrated in FIG. 5, the next page appears at the same portion andzoom factor as the current page. However, it should be apparent to thoseskilled in the art that other choices can be implemented, such asresetting the view of the next page to the default view of the firstpage. At step 670 the server creates a fourth HTML page with a URLcontaining an IIP request corresponding to the zoomed portion of theimage that is to appear in the next page, and transmits this page to theclient. At step 680 the client receives the fourth HTML page with theURL, and the web browser, upon processing the fourth page, accesses theURL that references the zoomed portion of the next image and sends itsIIP request to the image server. At step 690 the image server processesimage data to execute the IIP request and generate the requested image,and then transmits the requested image to the client. At step 700 theweb browser displays the fourth HTML page with a zoomed portion of thenext document page and its image.

Caching

The present invention uses caching in order to achieve improvedperformance. One of the advantages of client-side processing overserver-side processing is the ability to cache responses. As describedabove, client-side processing operates by transmitting individual tilesfrom the server to the client, and these tiles can be cached by theclient as they are received, thereby obviating the need to transmit themagain. The tile cache can be built up on the client, and as eachadditional interactive navigational request is processed, the client candetermine which tiles among the tiles necessary to fulfill the requestare already present in cache, and request from the server only thosetiles that are not available. Thus, for example, when a user pansslightly to the right, only the newly exposed tiles have to betransmitted from the server to the client.

The success of caching stems from the fact that a user interactivelynavigating through a large image typically returns to the same imagedata in a recurrent fashion. Zooming in and out, and panning up, down,left and right, typically lead through some of the same image data. Thisphenomenon is atypical for media such as video for which the usualviewing mode is simply to play the frames of the video forward, and thesame data is usually not accessed more than once in a single session.

Server-side processing is not as amenable to caching, since the regionscorresponding to each interactive user request do not necessarily repeatthemselves. That is, a user does not always return to the same exactregions he requested earlier, since regions are specified by floatingpoint numbers rather than integer-valued indices.

In order to optimize Universal Viewing for caching, the number ofpossible navigational options is restricted to a relatively small set.For example, when viewing a full image a Universal Viewing system canrestrict the possible zooms to enlargements of the nine regions:

RGN=0.0,0.0,0.5,0.5

RGN=0.0,0.25,0.5,0.5

RGN=0.0,0.5,0.5,0.5

RGN=0.25,0.0,0.5,0.5

RGN=0.25,0.25,0.5,0.5

RGN=0.25,0.5,0.5,0.5

RGN=0.5,0.0,0.5,0.5

RGN=0.5,0.25,0.5,0.5

RGN=0.5,0.5,0.5,0.5

Each of these regions has half of the full image height and half of thefull image width, and fitting them to the size of the full view windowgives the effect of an enlargement. To select one of these regions auser may click somewhere inside the image, and, depending on where themouse coordinates are, a corresponding region is selected. The simplestcorrespondence is to divide the image into a 3×3 “tic-tac-toe”partition, and to associate each of the above regions with acorresponding area of the 3×3 partition.

In turn, when viewing one of the above regions, the Universal Viewingsystem can offer the same nine relative sub-regions for further zoomingin. In addition, the Universal Viewing system can offer panningcapability from any one of the regions above to those regions thatoverlap with it. For example, if the current region being viewed is themiddle region

RGN=0.25,0.25,0.5,0.5

then a pan to the right corresponds to the region

RGN=0.25,0.5,0.5,0.5

and a pan to the bottom corresponds to the region

RGN=0.5,0.25,0.5,0.5

To select a navigational direction the user can click on one of eightdirectional arrows pointing in the compass directions N, NE, E, SE, S,SW, W and NW, and the Universal Viewing system moves the image 25%across and/or up or down in the direction of choice, until a boundary ofthe image is reached.

The advantage of such a system is that the possible regions are limited,and repeat themselves as the user zooms in and out and navigates in theeight compass directions. The JPEG images transmitted from the server tothe client can be cached using an indexing system based on the regions.Whenever a user returns to the same region, the cached data can be usedimmediately, avoiding the need for sending a request to the imageserver.

Universal Viewing with a restricted number of regions has lessfunctionality than a client-side processing solution using a plug-in orJava applet. For example, one cannot perform a continuous pan through animage using Universal Viewing as described above. However, for manyapplications the limited functionality suffices. One such application isinteractive viewing of documents, for which continuous navigation is nota requirement.

Web-Ready Documents

The scalable documents of the present invention are created by means ofa rendition tool that creates a “Web-Ready” document by converting astandard document containing images, such as the portable documentformat (PDF) of Adobe Systems, Inc., into a scalable document. Therendition tool operates by (i) extracting raster images embedded withinthe standard document, (ii) storing the raster images on an imageserver, and (iii) replacing the raster images with references to thestored images, the references containing IIP requests, and inserting thereferences into the document.

When a Web-Ready document is displayed on a video monitor, thehigh-resolution images originally contained within the standard documentare replaced with appropriate screen-size images. Moreover, in apreferred embodiment of the present invention, each page or portion of apage to be viewed is converted to a GIF image and embedded within anHTML page that contains buttons to assist with page turning, zooming,printing and thumbnail viewing. The HTML page is ready for display by aclient web browser, without the need for auxiliary client-side software.A new GIF image and HTML page are generated in response to each usernavigational request. GIF images are used instead of JPEG images whentext fonts are present, since JPEG compression tends to producenoticeable artifacts in text fonts.

Such a Web-Ready document can be viewed interactively by user navigationin a client-less environment. It can also be printed and saved at aspecified dpi resolution. In each case the raster images contained inthe pages of the document along with the fonts and vector graphicalobjects are scaled appropriately. In a preferred embodiment of thepresent invention, when a user saves a Web-Ready document, he can selecta desired resolution for the save operation. Upon save, the Web-Readyfile is converted back to a standard document with raster images, ratherthan references, embedded therewithin at the user-specified resolution.Similarly, in a preferred embodiment of the present invention, when auser prints a Web-Ready document, the document is converted back to astandard document with raster images embedded at the resolutionappropriate to the output device.

The conversion back from a Web-Ready document to a standard document isperformed by means of a delivery tool. The delivery tool reverses theoperations performed by the rendition tool, and operates by (i)processing the images stored on the image server to produceappropriately scaled images, (ii) removing the references to the storedimages, and (iii) embedding the appropriately scaled images into thedocument.

Reference is now made to FIG. 6, which is a simplified illustration of arendition tool for converting standard documents to scalable documents,and a delivery tool for converting scalable documents to standarddocuments. FIG. 6 illustrates a rendition tool that converts a standarddocument 710, such as a PDF document, containing an embedded image 720into a scalable document 730. To achieve scalability, image 720 isextracted from standard document 710 and replaced with a reference 740that contains image processing commands. In a preferred embodiment ofthe present invention the image processing commands include an IIP CVTcommand. Embedded image 720 is stored as an image 750 on an image server760. Image 750 may be a Flashpix image, obtained from embedded image 720by means of converter unit 770. Reference 740 and the image processingcommands therewithin refer to image 750.

In an alternate embodiment of the present invention, auxiliary data isgenerated with scalable document 730, such as (i) a document map 780that stores the position information for image 750 and any other imagesthat are removed from standard document 710, and (ii) an image-lessdocument 790. Scalable document 730 is Web-Ready for interactive viewingthrough a web browser.

Conversely, as described above, for print and save operations it isnecessary to generate a standard document, such as a PDF document, froma scalable Web-Ready document. FIG. 6 also illustrates a delivery toolthat converts scalable document 730 into a standard document 820 byusing a reference 800 contained within scalable document 730. Reference800 refers to stored image data, such as image 750, and contains imageprocessing commands operative on the stored image data. To accomplishthe conversion, reference 800 is removed from scalable document 730 andimage 810 is embedded in its stead, to produce a standard document 820.Embedded image 810 is generated from image 750 by image processor 830,using the image processing commands contained in reference 800, toproduce an image at the appropriate resolution for the printer or at theresolution specified by the user for saving. As such, embedded image 810may be at a different resolution than embedded image 720.

In an alternate embodiment of the present invention, standard document820 is constructed from image-less document 790, with document map 780being used to correctly position embedded image 810 within standarddocument 820.

It should be appreciated by those skilled in the art that whenconverting scalable document 730 to standard document 820, reference 800may be external to scalable document 730. Such a reference may begenerated directly from a print or delivery (i.e. save) request, basedupon characteristics of the printer or based upon a user-specifiedresolution for delivery, and need not be part of scalable document 730.In such a case it is unnecessary to remove reference 800 from scalabledocument 830. The image processing commands within reference 800 areused by image processor 830 to generate embedded image 810 from storedimage 750, and then image 810 is embedded into standard document 820.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the present invention includescombinations and sub-combinations of the various features describedhereinabove as well as modifications and extensions thereof which wouldoccur to a person skilled in the art and which do not fall within theprior art.

What is claimed is:
 1. A method for viewing a document located on aserver computer, comprising: sending by a client computer a page displayrequest to said server computer to view a page of a document, said pageincluding text and image data; creating by said server computer a layoutpage containing a reference to stored image data, the referenceincluding parameters for a rectangle designating an image portion;transmitting said layout page from said server computer to the saidclient computer; sending by said client computer an image data requestto a remote computer according to said reference to stored image data;transmitting requested image data from said remote computer to saidclient computer in response to said image data request; repeating saidsending a page display request, said sending an image data request bysaid client computer and transmitting requested image from said remotecomputer, for subsequent page display request for a magnified view ofthe page of the document; dynamically changing the parameters for arectangle corresponding to the subsequent page display request; andwherein the parameters for a rectangle and the parameters for a displaywidth and height are included within a CVT command from an InternetImaging Protocol.
 2. The method of claim 1 wherein the document is a PDFdocument.
 3. The method of claim 1 wherein the reference to stored imagedata is a URL.
 4. The method of claim 1 wherein the reference to storedimage data also includes parameters for a display width and height. 5.The method of claim 1 wherein the at least one image is a tiled image.6. The method of claim 1 wherein the at least one image is amulti-resolution image.
 7. The method of claim 6 wherein the at leastone image is a FLASHPIX image.
 8. The method of claim 1 wherein the atleast one image is a JPEG image.
 9. The method of claim 1 wherein the atleast one image is a TIFF image.
 10. The method of claim 1 wherein thelayout page specifies the positioning of the requested image data. 11.The method of claim 1 wherein the layout page is an HTML page.
 12. Themethod of claim 1 wherein the layout page also contains text characters.13. The method of claim 12 wherein each of the text characters isassociated with a corresponding font.
 14. The method of claim 12 whereinthe layout page specifies the positioning of the text characters. 15.The method of claim 1 and also including displaying the layout page andthe requested image data.
 16. The method of claim 1 and also includingprinting the layout page and the requested image data.
 17. The method ofclaim 1 wherein the remote computer is the server computer.
 18. Themethod of claim 1 wherein the remote computer is distinct from theserver computer.
 19. The method of claim 1 and also including processingby remote computer the stored image data to produce the requested imagedata.
 20. The method of claim 19 wherein the stored image data containsimage titles, and said processing includes: fetching appropriate imagetiles from the stored image data; combining the appropriate image tilesinto a single combined image; and converting the combined image into aspecified image format.
 21. The method of claim 20 wherein the specifiedimage format is the JPEG format.
 22. The method of claim 20 and alsoincluding: decompressing the appropriate image tiles; and compressingthe combined image.
 23. A system for viewing a document located on aserver computer, comprising: a client computer transmitter sending apage display request to the server computer to view a page document,said page including text and image data, and sending by said clientcomputer transmitter an image data request to a remote computeraccording to a reference to stored image data, said reference includingparameters for a rectangle designating an image portion; a layout pageproducer within said server computer creating a layout page containingsaid reference to stored image data; said server computer transmittertransmitting said layout page to said client computer; and said remotecomputer transmitter transmitting requested image data to said clientcomputer in response to said image data request; a reference generatordynamically changing said parameters for a rectangle corresponding to asubsequent page display request for a magnified view of the page of thedocument.
 24. The system of claim 23 wherein the document is a PDFdocument.
 25. The system of claim 23 wherein the reference to storedimage data is a URL.
 26. The system of claim 23 wherein the reference tostored image data also includes parameters for a display width andheight.
 27. The system of claim 23 wherein the at least one image is atiled image.
 28. The system of claim 23 wherein the at least one imageis a multi-resolution image.
 29. The system of claim 28 wherein the atleast one image is a FLASHPIX image.
 30. The system of claim 23 whereinthe at least one image is a JPEG image.
 31. The system of claim 23wherein the at least one image is a TIFF image.
 32. The system of claim23 wherein the layout page specifies the positioning of the requestedimage data.
 33. The system of claim 23 wherein the layout page is anHTML page.
 34. The system of claim 23 wherein the layout page alsocontains text characters.
 35. The system of claim 34 wherein each of thetext characters is associated with a corresponding font.
 36. The systemof claim 34 wherein the layout page specifies the positioning of thetext characters.
 37. The system of claim 23 and also including a videomonitor displaying the layout page and the requested image data.
 38. Thesystem of claim 23 and also including a printer printing the layout pageand the requested image data.
 39. The system of claim 23 wherein theremote computer is the server computer.
 40. The system of claim 23wherein the remote computer is distinct from the server computer. 41.The system of claim 23 and also including a processor within the remotecomputer processing the stored image data to produce the requested imagedata.
 42. The system of claim 41 wherein the stored image data containsimage tiles, and said processor includes: a data access unit fetchingappropriate image tiles from the stored image data; a combiner combiningthe appropriate image tiles into a single combined image; and aformatter converting the combined image into a specified image format.43. The system of claim 42 wherein the specified image format is theJPEG format.
 44. The system of claim 42 and wherein said processor alsoincludes: a decompress or decompressing the appropriate image tiles; anda compressor compressing the combined image.
 45. A scalable documentcomprising: at least one layout page; and at least one reference tostored image data, said at least one reference including at least onecommand for processing the stored image data; wherein the parameters fora rectangle and the parameters for a display width and height areincluded within said command, said command comprising a CVT command froman Internet Imaging Protocol.
 46. The scalable document of claim 45wherein the reference to stored image data is a URL.
 47. The scalabledocument of claim 45 wherein the command for processing the stored imagedata specifies a rectangular portion of a raster image and a displaywidth and height.
 48. The scalable document of claim 45 wherein the atleast one image is a tiled image.
 49. The scalable document of claim 45wherein the at least one image is a multi-resolution image.
 50. Thescalable document of claim 49 wherein the at least one image is aFLASHPIX image.
 51. The scalable document of claim 45 wherein the atleast one image is a JPEG image.
 52. The scalable document of claim 45wherein the at least one image is a TIFF image.
 53. The scalabledocument of claim 45 wherein the layout page specifies the positioningof the requested image data.
 54. The scalable document of claim 45wherein the layout page is an HTML page.
 55. The scalable document ofclaim 45 wherein the layout page also contains text characters.
 56. Thescalable document of claim 55 wherein each of the text characters isassociated with a corresponding font.
 57. The scalable document of claim55 wherein the layout page specifies the positioning of the textcharacters.
 58. A method for converting a document containing at leastone image into a scalable document, comprising: extracting at least oneimage from the document; storing the at least one image as stored imagedata; replacing said at least one image by at least one reference tostored image data, said at least one reference containing at least onecommand for processing said stored image data; and wherein theparameters for a rectangle and the parameters for a display width andheight are included within said command, said command comprising a CVTcommand from an Internet Imaging Protocol.
 59. The method of claim 58wherein the document is a PDF document.
 60. The method of claim 58wherein the stored image data is tiled image data.
 61. The method ofclaim 58 wherein the stored image data is multi-resolution image data.62. The method of claim 61 wherein the stored image data is FLASHPIXimage data.
 63. The method of claim 58 wherein the stored image data isJPEG image data.
 64. The method of claim 58 wherein the stored imagedata is a TIFF image data.
 65. The method of claim 58 wherein thereference to the stored image data is a URL.
 66. The method of claimwherein the command for processing the stored image data specifies arectangular portion of a raster image and a display width and height.67. A system for converting a document containing at least one imageinto a scalable document, comprising: an object extractor extracting atleast one image from the document; a storage device for storing said atleast one image as stored image data; a reference inserter replacingsaid at least one image by at least one reference to the stored imagedata, said at least one reference containing at least one command forprocessing said stored image data; and wherein the parameters for arectangle and the parameters for a display width and height are includedwithin said command, said command comprising a CVT command from anInternet Imaging Protocol.
 68. The system of claim 67 wherein thedocument is a PDF document.
 69. The system of claim 67 wherein thestored image data is tiled image data.
 70. The system of claim 67wherein the stored image data is multi-resolution image data.
 71. Thesystem of claim 70 wherein the stored image data is FLASHPIX image data.72. The system of claim 67 wherein the stored image data is JPEG imagedata.
 73. The system of claim 67 wherein the stored image data is a TIFFimage data.
 74. The system of claim 67 wherein the reference to thestored image data is a URL.
 75. The system of claim 67 wherein thecommand for processing the stored image data specifies a rectangularportion of a raster image and a display width and height.
 76. A methodfor converting a scalable document into a standard document using atleast one reference to stored image data, the scalable documentcontaining at least one layout page, and the at least one referenceincluding at least one command for processing said stored image data,comprising: processing said stored image data in accordance with said atleast one command, producing at least one image; and positioning said atleast one image within the scalable document according to positioninginstructions within the layout page; and wherein the parameters for arectangle and the parameters for a display width and height are includedwithin said command, said comprising a CVT command from an InternetImaging Protocol.
 77. The method of claim 76 and also includingconverting the scalable document into a format of the standard document,following said positioning.
 78. The method of claim 76 wherein thestandard document is a PDF document.
 79. The method of claim 76 whereinsaid processing extracts a specified rectangular portion of an image ata specified width and height.
 80. The method of claim 76 and alsoincluding printing the standard document.
 81. The method of claim 76 andalso including saving the standard document on a computer.
 82. A systemfor converting a scalable document into a standard document using atleast one reference to stored image data, the scalable documentcontaining at least one layout page, and the at least one referenceincluding at least one command for processing the stored image data,comprising: an image processor processing said stored image data inaccordance with the at least one command, producing at least one image;an image positioner positioning said at least one image within thescalable document according to positioning instructions within thelayout page; and wherein the parameters for a rectangle and theparameters for a display width and height are included within saidcommand, said command comprising a CVT command from an Internet ImagingProtocol.
 83. The system of claim 82 and also including a documentformat converter converting the scalable document into a format of thestandard document.
 84. The system of claim 82 wherein the standarddocument is a PDF document.
 85. The system of claim 82 wherein saidimage processor extracts a specified rectangular portion of an image ata specified width and height.
 86. The system of claim 82 and alsoincluding a printer for printing the standard document.
 87. The systemof claim 82 and also including a computer for saving the standarddocument.
 88. A machine readable medium having executable computerprogram instructions which when executed on a processing system causethe processing system to perform a method comprising: sending by aclient computer a page display request to a first remote computer toview a page of a document, said page including text and image data;receiving at said client computer in response to said page displayrequest, the layout page containing a reference to stored image datafrom said first remote computer, said reference including parameters fora rectangle designating an image portion; receiving a requested imagedata at said client computer in response to an image data request to asecond remote computer according to said reference to stored image data;repeating said sending a page display request and sending an image datarequest by said client computer and receiving a requested image datafrom said second remote computer, for subsequent page display requestfor a magnified view of the page of the document; dynamically changingthe parameters for a rectangle corresponding to the subsequent pagedisplay request; and wherein the parameters for a rectangle and theparameters for a display width and height are included within a CVTcommand from an Internet Imaging Protocol.
 89. The machine readablemedium of claim 88 wherein the reference to stored image data alsoincludes parameters for a display width and height and wherein saidrequested image data is received from a second remote computer.
 90. Themachine readable medium of claim 89 wherein the parameters for arectangle and the parameters for a display width and height are includedwithin a CVT command from an Internet Imaging Protocol.